The purpose of this file is to present links and other information to support the implementation of the Dallas 1-Wire system components for weather sensors and other types of instruments.
|Dallas Semiconductor - Supplier
of the 1-Wire components and weather station kits. The basic weather station kit
measures wind speed, wind direction, and the temperature inside the instrument. Also
available is a tipping-bucket type 1-Wire Rain Gauge. These instruments are well
made, and are a good value at the prices. See
below for links to the DS specification sheets and application notes.
Here is a threaded mail archive / discussion on the implementation of 1-Wire weather instruments problems and solutions.
Point Six, Inc. offer a variety of 1-Wire sensors. See the link below to the PSix application notes, which include hints for a successful 1-Wire network.
Here is one implementation of a Dallas 1-Wire weather station for APRS by Will, N0XGA, and Russ, KB0TVJ (wind direction and speed, plus temperature; they are thinking about barometric pressure). The authors feed the output to a controller (Motorola 6808). TAPR has a kit available.
Distributors of 1-Wire components
The weather station kits are available directly from Dallas Semiconductor in Dallas, Texas in the U.S.A. Link to the DS Weather Station and Rain Gauge kits. ( As of July 30th, 2000 Dallas is out of stock on the basic weather station kit. Future availability from DS at the previous price is not known at present. The rain gauge kit is still available.)
DS has announced the availability of a 1-Wire Relative Humidity module which can be ordered directly from DS, for $20 US. See the DS iButton web site for details.
Another manufacturer has stepped
into the breach .....
Distributors of Dallas 1-Wire
electronic components in Canada are :
In the Ottawa ON area, these distributors are at the following locations:
For the locations of these distributors in other parts of Canada, please send me an Email.
Specifications and Application Notes. These are Acrobat .pdf files.
Some of the the 1-Wire parts of particular interest are:
The DS2401 can be used to indicate whether a door or window
alarm circuit in a 1-Wire network is open or closed, as an example.
Parallax has a new 'Super Stamp' processor, the Basic Stamp II Plus. The BS II+ will support the Dallas iButton and 1-Wire systems, in addition to other features. It comes in 24pin and 40pin (more I/O) versions. Check the Parallax web site for details. This controller should permit putting together an environmental monitoring station using a combination of DS 1-Wire and 'conventional' sensors.
Now here's a neat gadget - for designing a 1-Wire network with a microcontroller or with a PC - the Point Six HA7S - a TTL to 1-Wire Host Adapter. This small 6-pin SIP module accepts ASCII commands, controls the 1-Wire bus, and provides a direct connection to a UART or microprocessor I/O. It relieves the host of generating the time-critical 1-Wire waveforms and it will support all 1-W devices, up to 100 devices and up to 2000 feet of CAT. 5 twisted pairs cable. Check the full description on the Point Six web site. This is advertised at $28.95US each. It looks pretty pricey at first glance, but it might permit the use of relatively slow controllers such as the Parallax Basic Stamp II for controlling a 1-Wire network - pretty handy too if you are not a whiz at programming in assembler or C.
Dallas Semiconductor has a nifty kit for the evaluation of the DS2450 quad analogue to digital converter. This kit (the DS2450K) includes a circuit board, power supply, PC DB9 serial cable, PC software and a thermocouple. The circuit board is intended to demonstrate real-time measurements of voltage (0-5V), current (0-20mA), ambient light level, temperature and external sensors. The DS2450K has on (the circuit) board a DS2450 quad A/D convertor, a DS1820 digital thermometer, a DS2406 dual addressable switch, a DS275 line-powered RS-232 transceiver and an HA7S, PLUS a solid-state relay (140 VAC at 3 A ), plus a terminal block for connections to external components. All this for $49.00US.
On the DS2450K board, the four inputs to the DS2450 are set up as follows:
The software included with the DS2450K (runs under Windows 95/98) monitors the four analogue input channels of the DS2450, does real-time graphs of each channel, logs data from any channel, and has a built-in PID loop controller and graphing [Proportional (the comparative relation of setpoint to error) Integral (accumulated average of errors over time) Derivative (rate of change of errors over time)].
Measuring Atmospheric Pressure
Here are two designs for measuring Atmospheric Pressure using the Motorola MPX4115 series of sensors and the DS2438 A/D converter. In each case the output of the MPX4115 is scaled with an operational amplifier to expand the voltage range of interest for atmospheric pressure. These use the DS2438 1-Wire ADC.
This is a third design by Simon Atkin using a DS2760 rather than a 2438. The circuit board design is shown, but no schematic information is available at present.
Counting Lightning Strikes
Here is a design for a lightning detector using the Dallas Semiconductor 1-Wire technology at <http://www.timbitson.com/weather/owlm/index.html>.
- More information to follow -
|Go to the Weather and Environmental Monitoring Introductory Page.||Go to the Notes and Links - Commercial and Kit Stations Page.||
Go to the Notes and Links - Sensors Page.
to the West Carleton
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Graham Ide VE3BYT